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Alteration of clay minerals in a sedimentary caprock and its use in geothermal prospecting: an example from Mt. Amiata

Published online by Cambridge University Press:  09 July 2018

S. Battaglia*
Affiliation:
Istituto di Geoscienze e Georisorse, Italian National Research Council, Via Moruzzi 1, 56124, Pisa, Italy
F. Gherardi
Affiliation:
Istituto di Geoscienze e Georisorse, Italian National Research Council, Via Moruzzi 1, 56124, Pisa, Italy
G. Gianelli
Affiliation:
Istituto di Geoscienze e Georisorse, Italian National Research Council, Via Moruzzi 1, 56124, Pisa, Italy
L. Leoni
Affiliation:
Dipartimento di Scienze della Terra, Università di Pisa, Via S. Maria 53, 56126, Pisa, Italy
M. Lezzerini
Affiliation:
Dipartimento di Scienze della Terra, Università di Pisa, Via S. Maria 53, 56126, Pisa, Italy

Abstract

This research work deals with chlorite-vermiculite mixed-layer stability under hydrothermal and metamorphic conditions. We used as a case study a clayey flysch unit cropping out in an active geothermal area near to a Recent volcano (Mt. Amiata) in central Italy. The geothermal gradient is higher than the world average and temperatures over 100°C can occur at less than 1 km depth. The mineralogical data, obtained from X-Ray Power Diffraction (XRPD) analysis of clay samples from the same geologic unit, show that the primary anchimetamorphic mineral assemblage (illite, chlorite, illite-smectite mixed layers) is accompanied by secondary phases, such as chlorite-vermiculite mixed-layers and calcite. Reactive flow modelling was used to outline a realistic water-rock (W/R) interaction process able to generate the new minerals. In the numerical simulation, the pristine shale was made to react with a local thermal spring, at an estimated but realistic carbonate reservoir temperature. The simulation predicts that, at a temperature of 120°C, clinochlore dissolves and vermiculite crystallizes, a good proxy of the chlorite-vermiculite crystallization process. Under low water/rock conditions the proportions of the clay minerals (illite, chlorite, smectite and vermiculite) are comparable with the analytical results. The simulation also shows that temperatures higher than 120°C enhance the vermiculite formation. We conclude that the chlorite-vermiculite mixed-layers formed in the recent past due to the upflow of thermal water which permeated the flysch unit. This result indicates that the alteration of the clayey cap-rocks of geothermal reservoirs is enhanced by the interaction with geothermal fluids, and can be used as a prospecting tool.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2013

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References

Árkai, P. (1991) Chlorite crystallinity: an empirical approach and correlation with illite crystallinity, coal rank and mineral facies as exemplified by Palaeozoic and Mesozoic rocks of northeast Hungary. Journal of Metamorphic Geology, 9, 723–734.Google Scholar
Atkinson, P.G., Celati, R., Corsi, R., Kucuk, F. and Jr.Ramey, H.J. (1978) Thermodynamic behaviour of the Bagnore geothermal field. Geothermics, 7, 185–208.Google Scholar
Bagnoli, G., Gianelli, G., Puxeddu, M., Rau, A., Squarci, P. & Tongiorgi, M. (1980) Segnalazione di una potente successione clastica di eta probabilmente Carbonifera nel basamento della Toscana meridionale. Memorie Società Geologica Italiana, 21, 127–136.Google Scholar
Bailey, S.W. & Riley, J.F. (1977) An unusual chlorite from Western Australia. Mineralogical Magazine, 41, 541–544.Google Scholar
Baldi, P., Bellani, S., Ceccarelli, A., Fiordelisi, A., Squarci, P. & Taffi, L. (1993) Nuovi Dati Geotermici nell’Area ad Ovest del Monte Amiata. Atti del 12° Convegno Annuale del Gruppo Nazionale di Geofisica della Terra Solida.Google Scholar
Battaglia, S., Gherardi, F., Gianelli, G., Leoni, L. & Origlia, F. (2007) Clay mineral reactions in an active geothermal area (Mt. Amiata, southern Tuscany, Italy). Clay Minerals, 42, 353–372.Google Scholar
Bernabini, M., Bertini, G., Cameli, G.M., Dini, I., Orlando, L. (1995) Gravity interpretation of Mt. Amiata Geothermal area (central Italy). Proceedings of the World Geothermal Congress, 1995. Florence, Italy, May 1995, ISBN 0-473-03123-X, 859–862.Google Scholar
Bertini, G., Cappetti, G., Dini, I. & Lovari, F. (1995) Deep drilling results and updatingof geothermal knowledge of the Monte Amiata area. Proceedings of the World Geothermal Congress, 1995. Florence, Italy, May 1995, 1283–1291.Google Scholar
Bettison, L.A. & Schiffman, P. (1988) Compositional and structural variations of phyllosilicates from the Point Sal ophiolite, California. American Mineralogist, 73, 62–76.Google Scholar
Bonciani, F., Callegari, I., Conti, P., Cornamusini, G. & Carmignani, L. (2005) Neogene post-collisional evolution of the internal Northern Apennines: insights from the upper Flora and Albegna valleys (Mt. Amiata geothermal area, southern Tuscany). Bollettino Società Geologica Italiana, Special Issue, 3, 103–118.Google Scholar
Brindley, G.W. & de Souza, J.V. (1975a) A goldencolored ferri-nickel chloritic mineral from Morro de Niquel, Minas Gerais, Brasil. Clay Minerals, 23, 11–15.Google Scholar
Brindley, G.W. & de Souza, J.V. (1975b) Nickel-bearing montmorillonites and chlorites from Brazil, with remarks on schuchardtite. Mineralogical Magazine, 40, 141–152.Google Scholar
Cho, M., Liou, J.G. & Bird, D.K. (1988) Prograde phase relations in the State 2-14 well metasandstones, SaltonSea geothermal field, California. Journal of Geophysical Research, 93, 13081–13103.Google Scholar
Cruz, M.D.R. (1999) New data for metamorphic vermiculite. European Journal of Mineralogy, 11, 533–548.CrossRefGoogle Scholar
Cruz, M.D.R., Puga, E., Aguirre, R., Vergara, M. & Morata, D. (2002) Vermiculite-like minerals in lowgrade metasediments from the Coastal Range of central Chile. Clay Minerals, 37, 221–234.Google Scholar
Dubińska, E. (1984) Interstratified minerals with chlorite layers from Szklary near Zabkowice Ślaskie (Lower Silesia) Archiwum Mineralogiczne, 39, 5–23.Google Scholar
Duclox, J, Meunier, A. & Velde, B. (1976) Smectite, chlorite and a regular interstratified chlorite-vermiculite in soils developed on a small serpentinite body: Massif Central, France. Clay Minerals, 11, 121–135.Google Scholar
Franceschelli, M., Pandeli, E., Puxeddu, M., Porcu, R. & Fadda, S. (1994) Illite crystallinity in pelitic and marly rocks from the Northern Apennines (southern Tuscany and Umbria, Italy). Neues Jahrbuch für Minereralogie, Monatshefte, 367–384.Google Scholar
Frondini, F., Caliro, S., Cardellini, C., Chiodini, G. & Morgantini, N. (2009) Carbon dioxide degassing and thermal energy release in the Monte Amiata volcanic-geothermal area. Applied Geochemistry, 24, 860–875.Google Scholar
Gianelli, G. (2008) A comparative analysis of the geothermal fields of Larderello and Mt. Amiata, Italy. Pp. 59–85 in: Geothermal Energy Research Trend (H.I. Ueckermann, editor), Chapter 3.Google Scholar
Gianelli, G., Mekuria, N., Battaglia, S., Chersicla, A., Garofano, P., Ruggeri, G., Manganelli, M. & Gebregziabher, Z. (1998) Water-rock interaction and hydrothermal mineral equilibria in the Tendaho geothermal system. Journal of Volcanology and Geothermal Research, 86, 253–276.Google Scholar
Harvey, R.D. & Beck, C.W. (1962) Hydrothermal regularly interstratified chlorite-vermiculite of tobermorite in alteration zones at Goldfield, Nevada: Clays and Clay Minerals, 9, 343–354.Google Scholar
Harvey, C.C. & Browne, P.R.L. (1991) Mixed-layer clay geothermometry in the Wairakey geothermal field, New Zealand. Clays and Clay Minerals, 39, 614–621.Google Scholar
Hayes, J.B. (1970) Polytypism of chlorite in sedimentary rocks. Clays and Clay Minerals, 18, 285–306.Google Scholar
Helgeson, H.C., Kirkham, D.H. & Flowers, D.C. (1981) Theoretical prediction of the thermodynamic behavior of aqueous electrolytes at high pressures and temperatures: IV Calculation of activity coefficients, osmotic coefficients, and apparent molal and standard and relative partial molal properties to 600°C and 5 kb. American Journal of Science, 281, 1249–1516.CrossRefGoogle Scholar
Herbillon, A.J. & Makumbi, M.N. (1975) Weathering of chlorite in a soil derived from a chlorite schist under humid tropical conditions: Geoderma, 13, 89–104.Google Scholar
Hoogland, J.R. & Elders, W.A. (1978) Hydrothermal mineralogy and isotopic geochemistry in the Cerro Prieto Geothermal field, Mexico. I. Hydrothermal mineral zonation, Geothermal Resources Council, Transactions, 2, 283–286.Google Scholar
Krismannsdttir, H. (1975) Hydrothermal alteration of basaltic rocks in Icelandic geothermal areas. Pp. 41–445 in: Proceeding 2nd UN Symposium on Development and Use of Geothermal Resources. San Francisco, CA, 20–29 May.Google Scholar
Krumm, S. (1996) WINFIT 1.2: version of November 1966 (The Erlangen geological and mineralogical software collection) of ‘‘WINFIT 1.0: a public domain program for interactive profile-analysis under WINDOWS’’. XIII Conference on Clay Mineralogy and Petrology, Praha, 1994. Acta Universitatis Carolinae Geologica, 38, 253–261.Google Scholar
Lasaga, A.C. (1984) Chemical kinetics of water-rock interactions. Journal of Geophysical Research, 89, 4009–4025.Google Scholar
Laurenzi, M.A. & Villa, I.M. (1991) The age of the early volcanic activity at Monte Amiata volcano, Tuscany: evidence for a paleomagnetic reversal at 300 ka bp. Plinius, 6, 160–161.Google Scholar
Leoni, L., Marroni, M., Sartori, F. & Tamponi, M. (1996) Metamorphic grade in metapelites of the Internal Liguride Units (Northern Apennines, Italy) European Journal of Mineralogy, 8, 35–50.Google Scholar
Leoni, L., Sartori, F. & Tamponi, M. (1998) Compositional variation in K-white micas and chlorites coexisting in Al-saturated metapelites under late diagenetic to low-grade metamorphic conditions (Internal Liguride Units, Northern Apennines, Italy). European Journal of Mineralogy, 10, 1321–1339.Google Scholar
Lezzerini, M., Sartori, F. & Tamponi, M. (1995) Effect of amount of material used on sedimentation slides in the control of illite ‘crystallinity’ measurements. European Journal of Mineralogy, 7, 819–823.CrossRefGoogle Scholar
Lichtner, P.C., Steefel, C.I. & Oelkers, E.H. (1996) Reactive transport in porous media. Reviews in Mineralogy, 34. Mineralogical Society of America, 438 pp.Google Scholar
Liotta, D. (1996) Analisi del settore Centro-Meridionale del Bacino Pliocenico di Radicofani (Toscana Meridionale). Bollettino della Societá Geologica Italiana, 115, 115–143.Google Scholar
Marinelli, G. (1967) Genèse des magmas du volcanisme Plio-quaternaire des Apennines. Geologische Rundshau, 57, 127–141.Google Scholar
McDowell, S.D. & Elders, W.A. (1980) Authigenic layer silicate minerals in borehole Elmore 1, Salton Sea geothermal field, California, USA. Contributions to Mineralogy and Petrology, 74, 293–310.CrossRefGoogle Scholar
McDowell, S.D. & Elders, W.A., (1983) Authigenic layer silicate minerals in borehole Elmore #1, Salton Sea geothermal field, California American Mineralogist, 68, 1146–1159.Google Scholar
Marinelli, G. (1975) Magma evolution in Italy. Pp. 165–219 in: Geology of Italy (F. Ricci Lucchi & C. R. Squires, editors), Tripoli.Google Scholar
Mazzuoli, R. & Pratesi, M. (1963) Rilevamento e studio chimico petrografico delle rocce vulcaniche del Monte Amiata. Atti Societá Toscana Scienze Naturali, Serie A, 70, 355–429.Google Scholar
Minissale, A. (2004) Origin, transport and discharge of CO2 in Central Italy. Earth-Science Reviews, 66, 89–141.Google Scholar
Moore, M.D. & Reynolds, R.C. (1997) X-ray Diffraction and the Identification and Analysis of Clay Minerals. Oxford University Press, Oxford-New–York, 378 pp.Google Scholar
Muffer, P.J.L.& White, D.E. (1969) Active metamorphism of upper Cenozoic sediments in the Salton Sea geothermal field at the Salton Trough, southeastern California, Geological Society of America Bulletin, 80, 157–182.Google Scholar
Nieto, F., Pilar Mata, M., Baulutz, B., Giorgetti, G., Árkai, P. & Peacor, D.R. (2005) Retrograde diagenesis, a widespread process on a regional scale. Clay Minerals, 40, 93–104.Google Scholar
Palandri, J.L. & Kharaka, Y.K. (2004) A compilation of rate parameters of water-mineral interaction kinetics for application to geochemical mixed-layer. US Geological Survey Open File Report 2004-1068, 64 pp.Google Scholar
Pandeli, E., Puxeddu, M., Gianelli, G., Bertini, G. & Castellucci, P. (1988) Paleozoic sequences crossed by deep drilllings in the Monte Amiata geothermal region (Italy). Bollettino Societá Geologica Italiana, 107, 593–606.Google Scholar
Pandeli, E., Puxeddu, M. & Ruggeri, G. (2001) The metasiliciclastic-carbonate sequence of the Acquadolce unit (eastern Elba Island): new petrographic data and paleogeographic interpretation. Ofioliti, 26, 207–218.Google Scholar
Pandeli, E., Bertini, G., Castellucci, P., Morelli, M. & Monechi, S. (2005) The sub-Ligurian and Ligurian units of the Mt. Amiata geothermal Region (southeastern Tuscany): new stratigraphic and tectonic data and insight into their relationships with the Tuscan Nappe. Bollettino Societá Geologica Italiana, Special Issue, 3, 55–71.Google Scholar
Patrier, P., Papapanagiotou, P., Beaufort, D., Traineau, H., Bril, H. & Rojas, J. (1996) Role of permeability versus temperature distribution of the fine (< 0.2 mm) clay fraction in the Chipilapa geothermal system (El Salvador, Central America). Journal of Volcanology and Geothermal Research, 72, 101–120.Google Scholar
Jr.Reynolds, R.C. (1985) NEWMOD: a computer program for the calculation of the basal diffraction intensities of mixed-layered clay minerals. R.C. Reynolds, 8 Brook Rd., Hanover, New Hampshire, USA.Google Scholar
Schiffman, P., Elders, T.M, William, A.E., McDowell, S.D. & Bird, D.K. (1984) Active metasomatism in the Cerro Prieto geothermal system, Baja California, Mexico: a telescoped low-pressure, low-temperature metamorphic facies series. Geology, 12, 12–15.Google Scholar
Schiffman, P. & Fridleifsson, G.O. (1991) The smectitechlorite transition in drillhole NJ-15, Nesjavellir geothermal field, Iceland: XRD, BSE and electron microprobe investigations. Journal of Metamorphic Geology, 9, 679–696.Google Scholar
Senkayi, A.L., Dixon, J.B. & Hossner, L.R. (1981) Transformation of chlorite to smectite through regularly interstratified intermediates. Soil Science Society of America Journal, 45, 650–656.Google Scholar
Steefel, C.I. & Lasaga, A.C. (1994). A coupled model for transport of multiple chemical species and kinetic precipitation/dissolution reactions with applications to reactive flow in single phase hydrothermal system. American Journal of Science, 294, 529–592.CrossRefGoogle Scholar
Teklemariam, M., Battaglia, S., Granelli, G. & Ruggieri, G. (1996) Hydrothermal alteration in the Aluto-Langano geothermal field, Ethiopia. Geothermics, 25, 679–702.Google Scholar
Velde, B. (1985) Clay Minerals (a physico-chemical explanation of their occurrence). Developments in Sedimentology, 40. Elsevier, Amsterdam, 427 pp.Google Scholar
Wiewiora, A. (1978) Ni-containing mixed-layer silicates from Szklary, Lower Silesia, Poland. Bulletin B.R.G.M., 3, 247–261.Google Scholar
Wolery, T.J., Jove-Colon, C.F. & Jareck, R.L. (2004) Qualification of thermodynamic data for geochemical mixed-layer of mineral-water interactions in dilute systems. ANL-WIS-GS-000003 REV00. Bechtel SAIC Company, Las Vegas, Nevada.Google Scholar
Xu, T., Apps, J.A. & Pruess, K. (2005) Mineral sequestration of carbon dioxide in a sandstone-shale system. Chemical Geology, 217, 295–318.Google Scholar